Development N17

Question 1

NS deals with a ________ environment

Answer 1

predictable

Question 2

Genetic determinants

Answer 2

most of the NS circuitry is established prenatally

Question 3

To deal with variations in habits, social environment, and physical attributes

Answer 3

the CNS maintains the ability to modify its connections, called adaptive adjustments

Question 4

Sensitive (critical) period

Answer 4

a period during which the capacity to adjust the NS circuitry in response to environment becomes limited

Question 5

A range of functional properties exist that a circuit could adopt, but if the appropriate experiences are not gained

Answer 5

circuits never attain the ability to process information in a typical fashion (impaired perception and behavior my be permanent)

Question 6

Experience shapes the visual cortex

Answer 6

depriving visual stimuli, results in cortical blindness, meaning the visual cortex no longer responds to visual input

Question 7

Hubel and Wiesel experiment proves the sensitive period

Answer 7

sutured monkey’s eye closed from 0-6 mo, animal was blind in that eye (cortical blindness)

Question 8

Congenital cataracts prove the sensitive period

Answer 8

Congenital cataracts removed during infancy results in full vision
Cataracts removed between 10-20 resulted in the inability to perceive shape and form

Question 9

Primary visual cortex

Answer 9

where information from two eyes first comes together; located in occipital lobe

Question 10

Visual experience early in life determines

Answer 10

how much visual cortex is devoted to processing input (via neurons in the LGN) and degree to which inputs are combined

Question 11

Layer 4 of the primary visual cortex

Answer 11

inputs from each eye cluster separately here, cells activated by each eye send input to common target cells above and below layer 4

Question 12

target cells above and below layer 4 of the primary visual cortex receive input from

Answer 12

BOTH the right and left eye (SMALL proportion respond exclusively to 1 eye)

Question 13

Binocular interaction

Answer 13

represented by the anatomical convergence on the same target

Question 14

Visual experience during the sensitive period

Answer 14

results in competition among afferents from the LGN to layer 4; normally the eyes are used equally resulting in equal ocular dominance columns

Question 15

Unequal balance between LGN afferents, due to vision impairments (monocular lid closure or cataracts) causes

Answer 15

impaired eye to lose the ability to drive layer 4 neurons in a large region of the cortex, LGN afferents from the normal eye GAIN ability to drive layer 4 neurons in a larger portion on the cortex

Question 16

Result from impaired eye on functional properties

Answer 16

activity in the visual cortex becomes driven largely by LGN afferents from the normal eye

Question 17

Axonal Architecture also changes if visual experience is withdrawn

Answer 17

axonal arbors of the LGN to layer 4 shrink in the impaired eye and expand in the normal eye

Question 18

In cats, 1 week deprivation of visual stimuli before 6 mo of age results in

Answer 18

complete loss of vision; whereas deprivation in an adult has no effect

Question 19

Critical period

Answer 19

period of maturation of cortical connections that is reliant on experience and stimuli

Question 20

Closure of sensitive periods

Answer 20

once adequate experience is perceived, the circuit IRREVERSIBLY commits to a pattern of connectivity

Question 21

Experience-driven sharpening of functional tuning

Answer 21

Major factor that decreases the plasticity of circuits; experience selects for anatomical connections and synaptic efficacy that refine excitatory and inhibitory connections, once this refining takes place it is difficult to alter via different experiences

Question 22

Deprivation of appropriate experiences causes the sensitive period to be ________

Answer 22

prolonged

Question 23

Raising cats in complete darkness would

Answer 23

prolong the critical period for ocular representation in the visual cortex

Question 24

What event triggers sensitive period adjustments?

Answer 24

powerful and repeated activation of neurons at the site where change takes place

Question 25

WIthout powerful and repeated stimuli

Answer 25

the pathway remains in an uncommitted state and capable of adjusting to experience

Question 26

Therapeutic aspect of the critical period

Answer 26

Someone with abnormal sensory input, can be deprived of all relevant sensory input until the abnormality is corrected, resulting in a prolonged sensitive period rather than a commitment to an abnormal pattern of connectivity

Question 27

Principles of developmental learning

Answer 27

Mainly regulated by genetic predisposition, limited range of stimuli can influence the circuit

Question 28

Filial imprinting

Answer 28

a rapid discrete time segment in which animals display imprinting on the first stimuli they see

Question 29

Babies in the process of imprinting

Answer 29

preferentially like images that resemble member of their own species

Question 30

Sensitive periods exist for:

Answer 30

fundamental capacities (stereoscopic vision, visual acuity, binocular coordination) and high-level capacities (social behavior, language, perception of shapes and faces)

Question 31

Language sensitive period

Answer 31

before 7 y/o a 1st or 2nd language results in thorough command of language; after 7 y/o the degree of proficiency decreases progressively (does not affect the ability to learn new words)

Question 32

Language is processed in the ____ hemisphere

Answer 32

left “dominant”

Question 33

If a 2nd language is learned before 7y/o the areas of the brain _________ with that of the 1st language. If a 2nd language is learned after 7 y/o the areas of the brain _________ with that of the 1st language

Answer 33

Overlap before 7y/o; do not overlap after 7y/o

Question 34

Social behavior depends on social experiences at specific periods of neuronal development

Answer 34

Social deprivation in the early months of life result in developmental delays and hospitalism syndrome, by age 2-3 the development was still delayed suggesting structural deficits in brain development

Question 35

Hospitalism syndrome

Answer 35

Rene Spitz’s term for infants that were raised in a hospital and lacked the appropriate social stimuli which went on to have retarded physical development, and disruption of perceptual-motor skills and language

Question 36

Theory of Mirror Neurons Circuitry

Answer 36

Specific type of neuronal population in the frontal and parietal lobes (also in areas related to visions and memory) necessary for imitation learning, understanding of others’ mood and actions, identity and imitation of adults

Question 37

Dysfunction of mirror neurons may lead to _____

Answer 37

autism and the inability to empathize

Question 38

Mirror neurons are subject to critical periods

Answer 38

plasticity is minimal following critical period

Question 39

Mirror neurons fire when

Answer 39

either the individual acts or when the same action done by another individual is perceived